1. Technical Field
The present invention relates to a liquid ejecting head and a liquid ejecting apparatus for ejecting liquid, and more particularly, to a liquid ejecting head which is useful as an ink jet recording head for discharging ink as liquid.
2. Related Art
In an ink jet recording head which is a representative example of a liquid ejecting head, generally, ink is supplied to a head body from an ink cartridge that is a liquid storage unit filled with ink via an ink supply needle that is an ink supply element inserted into the ink cartridge so as to be attachable and detachable and an ink channel provided in a supply member such as a cartridge case for holding the ink cartridge, and the ink, which is supplied to the head body by driving a pressure generating unit such as a piezoelectric element provided in the head body, is discharged from a nozzle.
In such an ink jet recording head, there is a problem in that if there are bubbles in ink in the cartridge, or bubbles, which are incorporated into the ink while the ink cartridge is attached or detached, are supplied to the head body, there is discharge defects such as dot missing due to the bubbles.
In order to solve the problem, there is disclosed an ink jet recording head provided with a filter for removing bubbles and dirt in ink between an ink supply needle inserted into an ink cartridge and a supply member (for example, refer to JP-A-2000-211130).
In the ink jet recording head disclosed in JP-A-2000-211130, the filter and the supply member are fixed to each other by thermal welding or the like, and the ink supply needle and the supply member are fixed to each other by ultrasonic welding.
However, in the configuration as disclosed in JP-A-2000-211130, there are problems in that since the filter is provided in a space where the ink supply needle of the supply member is fixed, the space according to an area of the filter is needed, and since a region for individually welding the ink supply needle and the filter to the supply member is needed, an interval between the adjacent ink supply needles cannot be reduced and this results in an increase in the size of a head.
Therefore, in order to solve the problem and achieve a reduction in the size of the ink jet recording head, there is proposed an ink jet recording head in which a filter is pinched between an ink supply needle and a supply member and in this state the ink supply needle and the supply member are formed integrally with each other by resin molding (for example, refer to JP-A-2009-132135).
The ink jet recording head disclosed in JP-A-2009-132135 employs a structure in which when the ink supply needle and the supply member are formed integrally with each other by resin molding, resin is wrapped to a part of a periphery of the filter pinched between the ink supply needle and the supply member so that the filter is fixed to the ink supply needle and the supply member also by the resin.
However, in the structure as disclosed in JP-A-2009-132135, since the filter is wrapped by the resin, a pinching portion of the filter is deformed due to an injection pressure or shrinkage of the filling resin during the resin molding, and accordingly twisting of the filter occurs. In addition, the filter is adhered to the channel. As a result, pressure loss increases, and simultaneously, there is a new problem in that defoaming performance is degraded.
This problem occurs also in the liquid ejecting head for ejecting liquid other than ink, as well as in the ink jet recording head.